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authorMa Wupeng <mawupeng1@huawei.com>2023-08-02 15:23:28 +0800
committerAndrew Morton <akpm@linux-foundation.org>2023-08-21 13:37:43 -0700
commit0db31d63f27e5b8ca84b9fd5a3cff5b12ac88abf (patch)
tree55ba23028df34aaf9829cbbdb0f3cbe7a92d47d4
parent18c59d58baa60a8bfaec58d29b6b94877664eed8 (diff)
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mm: disable kernelcore=mirror when no mirror memory
For system with kernelcore=mirror enabled while no mirrored memory is reported by efi. This could lead to kernel OOM during startup since all memory beside zone DMA are in the movable zone and this prevents the kernel to use it. Zone DMA/DMA32 initialization is independent of mirrored memory and their max pfn is set in zone_sizes_init(). Since kernel can fallback to zone DMA/DMA32 if there is no memory in zone Normal, these zones are seen as mirrored memory no mather their memory attributes are. To solve this problem, disable kernelcore=mirror when there is no real mirrored memory exists. Link: https://lkml.kernel.org/r/20230802072328.2107981-1-mawupeng1@huawei.com Signed-off-by: Ma Wupeng <mawupeng1@huawei.com> Suggested-by: Kefeng Wang <wangkefeng.wang@huawei.com> Suggested-by: Mike Rapoport <rppt@kernel.org> Reviewed-by: Mike Rapoport (IBM) <rppt@kernel.org> Reviewed-by: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Levi Yun <ppbuk5246@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
-rw-r--r--mm/internal.h1
-rw-r--r--mm/memblock.c5
-rw-r--r--mm/mm_init.c5
3 files changed, 11 insertions, 0 deletions
diff --git a/mm/internal.h b/mm/internal.h
index 5a03bc4782a2..a037b1b37f6d 100644
--- a/mm/internal.h
+++ b/mm/internal.h
@@ -1022,6 +1022,7 @@ static inline bool gup_must_unshare(struct vm_area_struct *vma,
}
extern bool mirrored_kernelcore;
+extern bool memblock_has_mirror(void);
static inline bool vma_soft_dirty_enabled(struct vm_area_struct *vma)
{
diff --git a/mm/memblock.c b/mm/memblock.c
index f9e61e565a53..913b2520a9a0 100644
--- a/mm/memblock.c
+++ b/mm/memblock.c
@@ -161,6 +161,11 @@ static int memblock_can_resize __initdata_memblock;
static int memblock_memory_in_slab __initdata_memblock;
static int memblock_reserved_in_slab __initdata_memblock;
+bool __init_memblock memblock_has_mirror(void)
+{
+ return system_has_some_mirror;
+}
+
static enum memblock_flags __init_memblock choose_memblock_flags(void)
{
return system_has_some_mirror ? MEMBLOCK_MIRROR : MEMBLOCK_NONE;
diff --git a/mm/mm_init.c b/mm/mm_init.c
index a2fbaa8d917f..2a19f3151661 100644
--- a/mm/mm_init.c
+++ b/mm/mm_init.c
@@ -376,6 +376,11 @@ static void __init find_zone_movable_pfns_for_nodes(void)
if (mirrored_kernelcore) {
bool mem_below_4gb_not_mirrored = false;
+ if (!memblock_has_mirror()) {
+ pr_warn("The system has no mirror memory, ignore kernelcore=mirror.\n");
+ goto out;
+ }
+
for_each_mem_region(r) {
if (memblock_is_mirror(r))
continue;